A new study suggests that drivers should worry about being picked up for driving under the influence - of a cold. A study from a British car insurance company and a university in Wales found that operating a car with a cold is the equivalent to driving after consuming four double whiskies. A cold can impair concentration levels, alertness and reaction times, just as alcohol does, according to the study.

But the reason for the appearance of driving drunk isn't due just to cold symptoms, said Dr. Greg Weisshaar, an urgent care physician for Park Nicollet in St. Louis Park, Minn. More likely it's from sleep deprivation caused by nighttime coughing, sniffling and aching, he said. Attempts to self-medicate can make the problem even worse. Some cold remedies contain 27 percent alcohol and many antihistamines cause drowsiness.
To prevent colds (and flashing lights in the rearview mirror), Weisshaar recommends frequent hand washing, getting plenty of sleep, eating healthful foods and exercising.